Forester UFS Wood Chip Boiler

Output range 180 to 2000 kW

Responsibility for energy and environment

The Forester wood chip boiler, operating with an under-feed stoker fuel feeding system, delivers market-leading efficiency and carbon-neutral heating. Our wide range of boilers will suit almost any customer’s space heating requirements.

Why choose Forester?

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SophisticatedEasy to use

• Low heating costs

• Efficient fuel usageduetomodulatingfuelfeedingsystem

• Low electrical consumption

• Grant funding available through theRenewableHeatIncentive

• Hinged doorforeasycleaningandmaintenance

• Assisted ash removalwithintegratedashbin

• Automatic ignition asstandard

• Low CO2 emissions

duetoexcellentcombustionefficiency

• Sustainable and renewable heat energy duetoourtreeplantingpartnershipwiththeWoodlandTrust

• Wood and sun – a winning combinationforafuture-proofedheatsupply

• Optimised fuel feeding systemswithunder-feedstokermodels

• Innovative touch screen controlsystem

• Operates with wood chip moisture content up to 35 w-%

Saving money and carbon together

Simple maintenance

Low impact on the environment

Versatile operation

Economical Ecological

Forester Highlyefficient,lowcarbonheatingforcommercialapplications

The complete Forester range extends from 180 kW to 2000 kW boilers for commercial use. At Hoval we have the perfect system for almost any requirement.

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Forester Advanced technology - sophisticated and easy to use

Pneumatic cleaning of fire tubes

Each fire tube within the heat exchanger is fitted with a pneumatic air blast nozzle mounted on the door at the front of the boiler. Short sequenced pulses of compressed air help to clear any ash particles that accumulate on the heat exchanger surface. This results in optimum boiler efficiency and reduces the frequency of manual intervention required throughout the year.

Unlike boilers which run on wood pellet fuel, this feature is a requirement for boilers running on wood chip. This is because the ash content of chip is generally much higher than the ash content of pellet.

Automation with efficiency over 90%

With the aid of the lambda sensor, the microprocessor-driven combustion control achieves optimal combustion conditions with minimum pollution.

It automatically detects variations in chip quality and compensates as necessary.

User-friendly operation High combustion efficiency – very low emissions

The Hoval Forester biomass boiler has been designed to run on virgin wood chip fuel - an energy source that is becoming increasingly available to meet the growing demand for carbon neutral fuels.

Seasoned - or partly dried timber - typically from managed sustainable woodland is shredded offsite into small evenly sized chips. The resulting fuel - wood chips - can then be brought to site in bulk delivery vehicles and tipped into a purpose designed fuel store.

The wood chip fuel is mechanically recovered from this store and fed into the boiler to burn and release its energy.

With its sophisticated combustion process, the Forester meets the requirements of EN303-5 Class 3 for emissions and efficiency.

• The combustion chamber optimises combustion with fully co-ordinated control of both primary and secondary combustion air

• Compact construction with integrated multi-cell cyclone particulate abatement technology

• Smoke tube heat exchangers encourage full use of primary heating surfaces, which are further optimised by air flow retarders

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De-ashing

The boilers can be arranged such that both grate ash and the fly ash are collected in bins adjacent to the boiler. Depending on the boiler model and client requirements, the ash is either collected in individual bins or a large common container mounted alongside the boiler.

Assisted Ignition

Assisted ignition of the wood chip within the boiler is achieved by utilising a hot air blower that initiates during start up. Once the fire bed is established, the combustion process becomes self-sustaining allowing the hot air blower to be disengaged and the boiler to operate under normal modulation.

Expertise in system combinations

With Hoval system technology and our experience, the Forester can be easily incorporated into other heat supply systems, matching your requirements.

• Bivalent systems with gas or oil boilers to help meet peak demand

• Integration of solar energy systems

Forester UFS (Under Feed Stoker)Advanced technology - sophisticated and easy to use

Fuel inlet via stoker feed screw

Secondary air

Cast burner retort withprimary air feed

Container for fine cyclone ash

3-pass heat exchanger

Front door with automatic pulse

cleaning of the fire tubes

Ash containerfor grate ash

Automatic discharge of ash

Exhaust gas cleaningusingmulti-cellcyclonewithautomaticdischargeoffineash

Ash grate

The Forester UFS is designed to burn wood chip fuel with a moisture content of between 10 and 35%.

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Model (UFS) 180 240 300 360 450 550 700 900 1200 1600 2000

•Nominal output (1) kW 180 240 300 360 450 550 700 900 1200 1600 2000

• Indicative Full Load Efficiency nCV (100% Output) % 91 91 91 91 91 91 91 91 91 91 91

• Indicative Part Load Efficiency nCV (30% Output) % 90 90 90 90 90 90 90 90 90 90 90

• Flue Gas Temperature Nominal Output °C 190 190 190 190 190 190 190 190 190 190 190

• Flue Gas Temperature Minimum Output °C 110 110 110 110 110 110 110 110 110 110 110

• Flue Gas Mass Flow at 9% O2

Nm3/h 390 520 650 780 975 1190 1520 1950 2600 3470 4340

• Maximum Boiler Flow Water Temperature °C 90 90 90 90 90 90 90 90 90 90 90

• Minimum Boiler Return Water Temperature °C 70 70 70 70 70 70 70 70 70 70 70

• Indicative Fuel Consumption (2) m3/h 0.21 0.28 0.35 0.42 0.53 0.65 0.82 1.06 1.30 1.90 2.30

• Boiler Water Content litres 830 830 1100 1100 1550 1550 2550 2550 3450 3650 5200

• Dry Weight (excluding stoker) kg 3450 3550 4400 4400 6600 6600 9900 9900 13000 15400 20900

• Flue Connection ID mm 180 200 200 250 300 300 300 350 400 450

• Minimum Buoyancy Required at Flue Outlet Pa 15 15 15 15 15 15 15 15 15 15 15

• Electrical Supply ph/v/Hz 3/400/50 3/400/50 3/400/50 3/400/50 3/400/50 3/400/50 3/400/50 3/400/50 3/400/50 3/400/50 3/400/50

Standard UFS Boiler has a maximum working pressure of 4.5 bar g and a design pressure of 5.0 bar g.Higher operating pressures and temperature available on request.

(1) The UFS boiler is designed to burn fuel with a moisture content of between 10 and 35 w-% as received and having a minimum net calorific value of 2.2 kWh/kg.The required wood chip designation is P45A to P63 as stated in BS EN 14961:2010. Ash content of fuel ≤ 1 w-% of dry basis.

(2) Indicative fuel consumption at nominal boiler output is based upon a standard P45A grade wood chip of M35 moisture content (35 w-% as received), processed from a coniferous wood species with an average calorific value of 0.65 MWh/m3. Actual values will vary depending on the wood species used, chip grade and moisture content.

Fuel Quality & Technical Data

For consistent and reliable boiler performance, sourcing the correct quality wood chip fuel is vital. As the graph shows, the moisture content of the wood has a marked influence on the overall energy available for the boiler. In addition, the wood chips should be evenly sized and free from foreign material (eg sand, soil etc) and not contaminated with stones, nails, metal fixings or other debris.

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4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

15 20 25 30 35 40 45 50 55 60

Indicative Effect of Moisture Content on the Calorific Value of Wood Fuel

% Moisture Content of Wood Chip Fuel

nCVkWh/kg

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Underfeed stoker UFS:Compact boiler with underfeed gasification furnace, flue gas passes with turbulators and integrated flue gas cleaning.

Controller:Optimised control and monitoring system with five control circuits. The interaction of these control circuits optimises the furnace values, guaranteeing a high degree of efficiency with low emissions.

Fuel feed:Depending on the nature of the material, by feed screw, double screw or scraper chain conveyor.

Automatic de-ashing:Compact boiler construction with underfeed gasification furnace, flue gas passes with turbulators and integrated flue gas cleaning system. Central or separate automatic de-ashing of grate and flue ash from the grate and multi-cyclone.

Fuel store:Rotary discharge system

Forester UFSOptimised fuel feeding systems

Making the right choice

At Hoval, we understand that it is important to choose fuel storage and conveyor systems to meet your requirements. We will carry out in-depth site surveys and layout reviews and suggest the best delivery system based on the space available and the fuel.

Rotary arm discharge system

The rotary arm discharge system is a good option for small to mid-range capacity systems.It is fitted with a jointed arm and discharge screw.

Typical application of Forester UFS

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Automatic de-ashing:Central or separate automatic de-ashing of grate and flue ash from the stoker grate and multi-cyclone.

Fuel feed:Via single or double screw transport augers depending on the nature of the fuel.

Store discharge:Via hydraulic feeding floor system into collection augers.

Wood chip fuel:Typically tipped into underground store.

Controller:Optimised control and monitoring system with five control circuits. Interaction of these circuits results in optimal values, guaranteeing a high degree of efficiencywith low emissions.

Push feeder floor discharge system

This push feeder floor is a hydraulically driven discharge system. It is a good option for larger capacity systems, guaranteeing the uninterrupted operation of the system.The pushrods slide on special insert parts.

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Efficient, easy to use and ecological Wood chips are the energy of the future

Efficient heating with wood chips

Unpredictable fluctuations in oil and gas prices are increasingly causing developers to consider wood as an alternative fuel to oil or gas.

The Forester simultaneously addresses ecological concerns, provides user-friendly technology, and meets demands for high energy efficiency.

Wood – a fuel with a future

The use of wood as a modern source of energy deserves consideration.

Locally sourced, carbon-neutral and renewable, wood offers an excellent price-performance ratio. The high performance Forester allows you to benefit from the advantages of chips as a modern energy source in buildings with large energy requirements.

Chips – bundles of natural energy

Wood chips are a processed form of wood fuel that can be used in automatic boiler equipment. Fuel quality is crucial for reliable operation of a wood chip boiler. The key parameters are material, size and moisture content.

If the chip has a high bark content this can cause excessive ash formation, which will reduce boiler efficiency. Chip size must be consistent for reliable operation of the fuel feed system.

Most importantly, moisture content of the chip affects the useful heat yield of the fuel. The higher the moisture content, the more energy that is required to deliver effective heating. It is also critical to note that supply of out of specification fuel to the boiler will result in poor combustion, variations in output performance and working life.

The UFS is designed to burn wood chip fuel with a moisture content of between 10 and 35%. In the event that wetter fuel is used in the UFS boiler then reduced flow temperatures and reduced thermal outputs will be evidenced.

Forester and Hoval system solutions A professional integrated approach

With the move towards renewable energy, an ever-evolving range of technologies is being integrated into building heating systems.

Forester and Solar are a perfect combination to cover additional heating and hot water demands.

By expanding the collector surface area, enough solar power can be generated to provide the required heat.

Forester and Solar combinations

Flexibility to suit any need

Hoval can control systems with up to five heat generators and ten mixing circuits. Therefore, a wide range of energy sources, including biomass, can be utilised together, delivering a well co-ordinated system to meet your heating demands.

Domestic hot water

Hoval offers a wide variety of domestic hot water storage units ranging from 160 to 10,000 litres.

Our extensive product range can provide solutions to meet most building conditions producing hot water as economically and ecologically as possible.

Hoval system technologies not only make energy source combination possible but have real economical and ecological benefits.

Fuel savings can be between 20 and 35 %, depending on the insulation. In low energy buildings, savings can even reach 50 %.

System technologies

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Technical advice

We are happy to assist you and your planning partners in developing intelligent systems, allowing you to take advantage of our expertise and the experience of our specialists.

One-stop shopping

With us you can easily incorporate gas, oil, heat pump, solar, CHP, or biomass energy solutions into your heating system.

Hoval LtdNorthgateNewark-on-TrentNottinghamshireNG24 1JNUnited Kingdom

Phone 01636 672 711Fax 01636 673 532email boilersales@hoval.co.ukwww.hoval.co.uk

Responsibilty for energy and environmentResponsibility for energy and environment

Hoval follows a policy of continued improvement and reserves the right to change specifications without notice.

After sales

For specialist commissioning and maintenance of your Hoval equipment, contact our service and spares department.

An expert partner